The Animal Cell

The Plant Cell

Tools of the Scientist Compound Light Microscope Dissecting Microscope Phase-Contrast Microscope Electron Microscope Microdissection Instruments Centrifuge/Ultracentrifuge Staining Computers Chromatography Electrophoresis Spectrophotometry

The Compound Light Microscope Uses 2 lenses or sets of lenses Light passes through specimens Magnification=Objective lens power X Ocular(eyepiece) power Resolution: The capacity of a microscope to show two points that are close together as two separate points

Compound Light Microscope Vocabulary Base Arm Body Tube Stage Stage Clips Nosepiece Coarse/Fine adjustment Mirror/Light Diaphragm Objective Lenses Ocular Lens

The Compound Light Microscope

The Compound Light Microscope Body Tube Ocular Course Adjustment Knob Fine Adjustment Knob Nosepiece Objective Lens Arm Stage Clips Stage Disk Diaphragm Base Lamp

Dissecting Microscope Also called a Binocular microscope Has a relatively low magnifying power, but……. Gives a 3-D image Used for relatively large, opaque specimens

Phase Contrast Microscope Unstained, living cells can be viewed Makes structures not normally seen with other microscopes visible by varying the light wavelengths

Electron Microscopes The best magnification of any other microscopes: 400,000X Only dead specimens can be viewed Specimen coated with metal, electrons are bounced off the surface Viewed on a monitor like a TV

Microdissection Instruments Used in conjunction with a microscope Can remove/transfer large cell organelles (like the nucleus)

Centrifuge /Ultracentrifuge Separates by density Can separate cell contents into layers of different densities Must balance tubes inside to avoid breakage

Staining Makes cell structures visible Methylene Blue and Iodine both make the nucleus more visible Iodine also highlights starch grains in plants, and makes cell walls more visible

Computers As well as storing huge amounts of information, computers can plot data when connected to probes, and make graphs Can be used as analytical tools Are a huge part in the Human Genome Project

Chromatography Separates different substances based on differences in absorption on a solid substrate (like chromatography paper)

Electrophoresis Separates substances in an electric field based on their charge or their size Protein Gel Electrophoresis DNA Electrophoresis (in agarose gel)

Spectrophotometry We can make inferences as to the makeup of a substance by analyzing what light wavelengths it absorbs